My players are gonna explore and hopefully free an old ruined castle from a pack of orcs.

I have a feeling they will want to appropriate the walls as their home and fancy themselves Castelans.

I have some rough estimates for the value of repairs that they will need to undertake to make their new home somewhere livable again.

The repairs that need to be done:
-freeing and terracing the road leading to the castle
-repairing and rebuilding the outer walls sections that crumbled
-minor repairs to three towers, one tower to be rebuilt
-rebuild the main hall
-reconsecrate and repair the chapel
-rebuild the stables
-rebuild the annex buildings

So I have some ideas but are there costs/rules somewhere to help me build a sheet of repairs and costs to present to the players and give them some incentives to go look for treasure?

Not adding anything of significance - I think Go0gleplex's answer pretty much nailed it shut, and well done on that - but with regard to the topic itself...man, this is one of those things that puts RPGs - and especially fantasy-based ones, in this situation - in a separate category of their own. In what other circumstances could people turn home renovation into a game, and potentially make it a pretty darned interesting one? Sure, there might be other factors intruding in the gaming narrative - monsters from the Ninth Circle of Hell invading, evil three-digit level tyrants kidnapping princesses on the way to their weddings, and so on - but such trivial incidents can be dealt with in between attending to the tower reconstruction and indoor plumbing innovations. Seriously, though, this is something that, if I was involved in, I'd take a real personal hand in making the best show I could; e.g., take online castle floorplan diagrams and display photos and start doing a mix-and-match of whatever seemed like it might be the most useful and/or dramatic. All congratulations, Greyblade, on giving your players a chance to take the option of doing something that might seem so pedestrian, but could end up becoming a major developmental, and group participation, root from which a gaming group draws its identity.

Greyblade wrote:...give them attachment to a place and leave the murder hobo days behind.

Greyblade, no kidding, I read this over and busted a gut laughing. Just picturing the boxed game, Murder Hobos: The RPG (not recommended for children under 12), the cover being a shot from the Hobo With A Shotgun faux trailer, and the back cover text, "Yes! Now you can wander the streets of America (or any fictional nation your GM creates) and kill with an eye toward accumulating riches! With statistics like Grunt Endurance (being able to walk for days and sleep outside without dying), Pathos (looking helpless and a victim of social injustice when you're begging at the streetcorner, despite the dozens of people you've killed), Sociopathology (the ability to kill without remorse and which mirrors the trait so many corporate raiders possess) and Who-Gives-A-F*** (being able to pretend to not care that you don't have the basic material possessions to build a life and impress people as to how tough you are), you'll be able to create a character that feels like a real life person! Whether it's just for being able to afford a spot for the night at that group room at the hostel (where there could be hobos equally dedicated to murdering you for your quarters and bus passes) or renting that one-bedroom basement apartment for a month, this is the game where you can wander without possessions, morals or long-term purposes in life! Get your dice and start rolling now!"

My group is slowly working towards the refurbishment of an abandoned cloister. So far they've only replaced some furnishings...the real work has yet to begin with the replacement of plumbing, un-blocking and restoration of windows, and cleaning out the foulness remaining in the cellars from the necromantic shadow cultist that had been working on corrupting the area.

"Rolling dice and killing characters since September 1976." "Author of Wardogs! and Contributor to Iron Stars and Starmada-Admiralty ed.""Certified crazy since 2009."